1. Field
An air conditioning system and a method of controlling an air conditioning system are disclosed herein.
2. Background
Air conditioners are appliances that maintain air within a predetermined space at a most proper state according to a use and purpose thereof. In general, such an air conditioner may include a compressor, a condenser, an expansion device, and evaporator. Thus, the air conditioner has a refrigerant cycle in which compression, condensation, expansion, and evaporation processes of refrigerant may be performed. Thus, the air conditioner may heat or cool a predetermined space.
The predetermined space may be variously provided according to a place at which the air conditioner is used. For example, when the air conditioner is disposed in a home or office, the predetermined space may be an indoor space of a house or building. On the other hand, when the air conditioner is disposed in a vehicle, the predetermined space may be an interior space in which a person rides.
When the air conditioner performs a cooling operation, an outdoor heat-exchanger provided in an outdoor unit or device may serve as a condenser, and an indoor heat-exchanger provided in an indoor unit or device may serve as an evaporator. On the other hand, when the air conditioner performs a heating operation, the indoor heat-exchanger may serve as the condenser, and the outdoor heat-exchanger may serve as the evaporator.
FIG. 1 is a schematic diagram of an air conditioning system according to a related art. Referring to FIG. 1, air conditioning system 1 may include an outdoor unit or device 2, in which a compressor and an outdoor heat exchanger may be provided, a plurality of distributor 3 connected to the outdoor device 1, and a plurality of indoor units or devices 4 respectively connected to the plurality of distributors 3 and in which indoor heat exchangers may be respectively provided. The air conditioning system 1 may perform in a simultaneous operation mode in which cooling and heating operations are simultaneously performed.
As illustrated in FIG. 1, the plurality of distributors 3 may include a first distributor 3a and a second distributor 3b. The plurality of indoor devices 4 may include a first indoor device 4a and a second indoor device 4b. The first distributor 3a may be connected to the first indoor device 4a, and the second distributor 3b may be connected to the second indoor device 4b. 
The plurality of distributors 3 may distribute refrigerant discharged from the outdoor device 2 into the plurality of indoor devices 4. The plurality of distributor 3 may be connected to the outdoor device 2 and the plurality of indoor devices 4 through tubes.
In detail, the outdoor device 2 and the plurality of distributors 3 may be connected to each other through three tubes. The three tubes may include a low-pressure gas tube 5, a liquid tube 6, and a high-pressure gas tube 7.
The low-pressure gas tube 5 may be a tube through which the refrigerant may flow until the refrigerant is introduced into the compressor after being evaporated in an evaporator in a refrigeration cycle. The liquid tube 6 may be a tube through which the refrigerant may flow after being condensed in a condenser. The high-pressure gas tube 7 may be a tube through which the refrigerant may flow until the refrigerant is introduced into the condenser after being compressed in the compressor. The three tubes may be branched and connected to the first distributor 3a and the second distributor 3b. 
One distributor of each of the plurality of distributors 3 and one indoor device of each of the plurality of indoor devices 4 may be connected to each other through two tubes. The two tubes may include a gas tube 8, through which a gaseous refrigerant may flow and a liquid tube 9, through which a liquid refrigerant may flow.
That is, in the air conditioning system according to the related art, the outdoor device 2 and the plurality of distributors 3 may be connected to each other through the three tubes, and the distributors 3 and the indoor devices 4 may be connected to the two tubes.
As described above, when the outdoor device 2 and the plurality of distributors 3 are connected to each other through the three tubes, the outdoor device 2 and the distributors 3 may be complicated in installation and assembly. In addition, as a number of welding portions to connect the tubes and the outdoor device (or the plurality of distributors) increases, installation reliability may deteriorate.
When the refrigeration cycle is performed in a state in which the indoor devices includes heating indoor devices and cooling indoor devices, that is, in a case of a main heating simultaneous operation, in which a heating operation is mainly performed using the heating indoor devices, and a cooling operation is performed using a portion of the cooling indoor devices, pressure loss in the outdoor device may occur, deteriorating simultaneous operation performance.
In detail, the refrigerant evaporated in the cooling indoor device and the refrigerant condensed in the heating indoor device may be mixed with each other to generate a two-phase refrigerant. The two-phase refrigerant may flow into the outdoor heat exchanger through the liquid tube. Pressure loss may occur in an expansion device reducing pressure, and thereby deteriorating operation performance.